For ChIP-Seq, cells were collected and cross-linked in 1% formaldehyde. After quenching the excess formaldehyde with 125 mM glycine, the fixed cells were washed, nuclei were isolated and then sheared in a Covaris E229 sonicator for 8 minutes to generate DNA fragments between ~ 200-1000 bp. After clarification of insoluble material by centrifugation, the chromatin was immunoprecipitated overnight at 4C with antibodies against Hdac3 or H3K27ac then bound to Protein A Dynabeads (Invitrogen). Antibody bound DNA were washed and treated with Proteinase K and RNase A and the purified ChIP DNA was used for library generation for subsequent sequencing. ChIP-Seq libraries were generated using the NuGen Ovation Ultralow Library System V2 following the manufacturer's instructions.